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Post-Newtonian Feasibility of the Closed String Massless Sector
Kang-Sin Choi1, Jeong-Hyuck Park2
1Scranton Honors Program, Ewha Womans University, Seodaemun-gu, Seoul 03760, Korea and Institute of Mathematical Sciences, Ewha Womans University, Seodaemun-gu, Seoul 03760, Korea.
Physical Review Letters
|August 26, 2022
Summary
This study tests string theory using double field theory and post-Newtonian analysis. Observations of the Eddington-Robertson-Schiff parameter gamma suggest an ultrarelativistic state in baryons or suppressed gluon condensate.
Area of Science:
- String theory
- Gravitational physics
- Cosmology
Background:
- Double Field Theory (DFT) offers a framework for string theory.
- Post-Newtonian (PN) analysis is crucial for testing gravity theories against observations.
- The Eddington-Robertson-Schiff (ERS) parameters (βPPN, γPPN) are key observational probes of gravitational theories.
Purpose of the Study:
- To perform a post-Newtonian analysis of Double Field Theory.
- To test string theory predictions in the gravitational sector against observational data.
- To identify the physical meaning of ERS parameters within DFT.
Main Methods:
- Post-Newtonian (PN) expansion of Double Field Theory.
- Identification of ERS parameters (βPPN, γPPN) with DFT charges (electric H flux, dilaton).
- Relating these parameters to the stress-energy tensor and imposing the weak energy condition.
Main Results:
- βPPN is identified with the electric H flux charge and shown to be equal to 1, consistent with the weak energy condition.
- γPPN is identified with the dilaton charge.
- The observational value of γPPN ≈ 1 is linked to specific physical conditions.
Conclusions:
- The study provides a test of string theory in the gravitational sector using observational constraints.
- The result βPPN=1 supports the weak energy condition within this framework.
- The observation γPPN≃1 implies either an ultrarelativistic equation of state in baryons or a suppressed gluon condensate, offering testable predictions.
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